|
14
KeyStudio User Guide
MIDI Messages In-Depth
10
Program & Bank Changes
When the MIDI standard was rst established, it enabled the user to access only 128 different sounds using program change
messages (0-127). As MIDI devices grew to be more sophisticated and contain more sounds, bank change messages were included
in an updated MIDI specication to allow for more than 128 sounds to be accessed.
The language MIDI uses to communicate between musical instruments only allows for program change commands 0-127, for a
total of 128 possible programs (127 programs + program “0” = 128 programs total). Because of inherent limitations of the MIDI
communication protocol, the number of directly accessible programs (using program change messages) cannot easily be expanded
beyond 128. Thus, a system of banks, with 128 sounds in each, has been created that enables manufacturers to overcome the 128-
sound MIDI limit.
128 banks with 128 sounds in each bank is the basic
principle used to expand the number of accessible
sounds. However, to avoid reaching the new limit of
the resulting 16,384 possible sounds (128 banks
x 128 programs) accessible using a bank change
combined with a program change, another layer
of banks was added. The result is a system of 128
banks that can contain 128 sub-banks in each
of them, which, in turn, can contain 128 sounds
(programs) within them.
Bank change messages are useful when calling
up sounds from a large library that may exist in a
particular sound module or software synth. For
example devices that are built with Roland’s GS
specication or Yamaha’s XG specication require
you to specify a bank change in order to access the
extra voices and effects that these devices provide.
MIDI CC 0 is the bank select MSB (Most Signicant
Byte) message. This MIDI message is 7-bit in size
and can be used to select any of 128 banks. This
message can be used in conjunction with MIDI CC
32 which is bank select LSB (Least Significant
Byte): a separate 7-bit message allowing additional
selection of any of another 128 sub-banks. The
combination of Bank MSB and LSB messages gives
a 14-bit message that can select any of a possible
16,384 banks. Each bank can in turn contain 128
possible sounds selected via a separate program
change MIDI message. This enables a user to
theoretically recall over two million programs directly,
using only MIDI commands. However, most devices
only use a few different banks, and allow you to
access them with either a Bank LSB message
or a Bank MSB message. Please consult your
synthesizer’s or software’s documentation for more
information on which type of bank change messages
it can process.
Bank MSB 0
Bank MSB 127
Bank LSB 127
Bank MSB 2
Bank LSB 0
Bank LSB 1
Bank LSB 2
Bank LSB 127
Bank LSB 0
Bank LSB 1
Bank LSB 2
Bank LSB 127
Bank LSB 0
Bank LSB 1
Bank LSB 2
Bank MSB 1
Bank MSB Bank LSB Program
Program 127
Program 0
Program 1
Program 2
Program 127
Program 0
Program 1
Program 2
Program 127
Program 0
Program 1
Program 2
Program 127
Program 0
Program 1
Program 2
Program 127
Program 0
Program 1
Program 2
Program 127
Program 0
Program 1
Program 2
Program 127
Program 0
Program 1
Program 2
Program 127
Program 0
Program 1
Program 2
Program 127
Program 0
Program 1
Program 2
To Next Page
Loading...
Need help?
General
